johnrlyons
Recruit
- Joined
- Apr 23, 2011
- Messages
- 1
Long story as short as I can make it....... the engine started running rough and would surge above 1,200-1,400 rpms, and would pop through the TBI at about 2,600 rpms and surge as well. But ran ok at trolling speed.
Got back to the dock and found one fuel injector was not firing, and also an anti-syphon valve had a small air leak and basically was disintegrating. Replaced the anti-syphon valve, all the fuel lines, Racor filter and Volvo filter in the fuel cell. Got 2 new injectors (ouch, not cheap) and also put in a new fuel cell which needed replacing anyway (I had the new one on hand). Also dismantled the TBI and cleaned everything with carb cleaner and q-tips. And cycled the fuel cell several times to be sure fuel was clean. Got a few particles but not much. Put it all together and it ran better but still surged and would pop under load at about 2,400-2,600 rpm's. And, would bog down and start to stall when first put in gear but would eventually surge after a couple seconds.
Put new distributor cap, wires, and rotor on...... same thing.
Replaced the throtle positioning sensor....... same thing.
Replaced the IAC sensor........ same thing.
At this point, it was beyond anything else I could do, so called in the calvery. The marine mechanic did diagnostic checks and no codes come up. He checked the low pressure and high pressure fuel lines and both were right on. Checked the timing and it was right on. Checked the MAP sensor and it seemed to be functioning correctly.
Did compression checks this afternoon and all were reasonable..... low of 165 and high of 180. Didn't think it was valves because the mechanic did new heads and valves 11 months ago (about 120 hrs).
The only other thing that has not been changed is the spark module on the distributor.
There are 2 ECU modules on this TBI.... VP part no's 3858887 and 3858888. From what I have found, they run about $1K each. The engine has aprox. 1,800 hrs on it and I'm afraid one or both of the modules may be shot. Plus, it looks like they are both out of production.
Does anyone know if the ECM's can be rebuilt/remanufactured if that is the problem?
The mechanic brought a laptop with recording diagnostic software today and recorded the boat at idle as well as in gear and is going to discuss with Volvo on Monday.
Oh yeah...... also, the gas is good. Ran it off a portable gas tank too, and it ran the same. So, gas problems have been ruled out as well.
Sorry for the long post, but any ideas? Any ideas if the ECM's are the problem? Can they be rebuilt?
Thanks,
John
Got back to the dock and found one fuel injector was not firing, and also an anti-syphon valve had a small air leak and basically was disintegrating. Replaced the anti-syphon valve, all the fuel lines, Racor filter and Volvo filter in the fuel cell. Got 2 new injectors (ouch, not cheap) and also put in a new fuel cell which needed replacing anyway (I had the new one on hand). Also dismantled the TBI and cleaned everything with carb cleaner and q-tips. And cycled the fuel cell several times to be sure fuel was clean. Got a few particles but not much. Put it all together and it ran better but still surged and would pop under load at about 2,400-2,600 rpm's. And, would bog down and start to stall when first put in gear but would eventually surge after a couple seconds.
Put new distributor cap, wires, and rotor on...... same thing.
Replaced the throtle positioning sensor....... same thing.
Replaced the IAC sensor........ same thing.
At this point, it was beyond anything else I could do, so called in the calvery. The marine mechanic did diagnostic checks and no codes come up. He checked the low pressure and high pressure fuel lines and both were right on. Checked the timing and it was right on. Checked the MAP sensor and it seemed to be functioning correctly.
Did compression checks this afternoon and all were reasonable..... low of 165 and high of 180. Didn't think it was valves because the mechanic did new heads and valves 11 months ago (about 120 hrs).
The only other thing that has not been changed is the spark module on the distributor.
There are 2 ECU modules on this TBI.... VP part no's 3858887 and 3858888. From what I have found, they run about $1K each. The engine has aprox. 1,800 hrs on it and I'm afraid one or both of the modules may be shot. Plus, it looks like they are both out of production.
Does anyone know if the ECM's can be rebuilt/remanufactured if that is the problem?
The mechanic brought a laptop with recording diagnostic software today and recorded the boat at idle as well as in gear and is going to discuss with Volvo on Monday.
Oh yeah...... also, the gas is good. Ran it off a portable gas tank too, and it ran the same. So, gas problems have been ruled out as well.
Sorry for the long post, but any ideas? Any ideas if the ECM's are the problem? Can they be rebuilt?
Thanks,
John